<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<script>

    var str = "abcdea";

    //给字符查索引(索引值为0,说明字符串以查询的参数为开头)
    console.log(str.indexOf("c"));
    console.log(str.lastIndexOf("c"));

    console.log(str.indexOf("a"));
    console.log(str.lastIndexOf("a"));


    //了解；数据传递的时候经常需要通过编码后在传递，接收后还需要反编译回来。
    var url = "http://www.itcast.cn?username='aaa'&password='123'";
    console.log(encodeURIComponent(url));
    console.log(decodeURIComponent(encodeURIComponent(url)));


</script>
</body>
</html>